It's not true. He was a merchant sailor. A good, respectable man who obeyed the law.
8 seconds sound clip from the Pirates of the Caribbean 1: The Curse of the Black Pearl movie soundboard.
You can hear this line at 00:49:12 in the Blu-ray version of the movie.
Quote context
[...]
- I knew him. Probably one of the few who knew him as William Turner.
- Everyone else just called him Bootstrap, or Bootstrap Bill.
- Good man. Good pirate. I swear, you look just like him.
- It's not true. He was a merchant sailor. A good, respectable man who obeyed the law.
- He was a bloody pirate, a scallywag.
- Put it away, son. It's not worth you getting beat again.
- You didn't beat me. You ignored the rules of engagement. In a fair fight, I'd kill you.
- That's not much incentive for me to fight fair, is it?
[...]